JP7564933B2 - Wear measurement method - Google Patents

Description

The present invention relates to a method for measuring wear.

A known method for measuring the amount of wear on the cutting edge of a grinding tool or the like involves imaging the cutting edge and calculating the amount of wear by analyzing the image data.

Patent Document 1 describes how a camera is placed directly opposite the cutting edge, the cutting edge is illuminated using a coaxial epi-illumination method or a small ring light, the cutting edge is imaged in this state, and the amount of wear is measured from the image data. It also describes how the amount of wear is measured by converting the image data into binary or multi-value data and determining the wear width of the flank of the cutting edge.

Patent Document 2 describes a method for extracting the contour line of the cutting edge, which serves as a reference for measuring the amount of wear, from an image of the cutting edge of a tool. Specifically, the extraction is performed as follows. First, three or more take-off lines that intersect in the cutting edge direction are extracted from the image of the cutting edge of the tool. Next, the line pixel data on the take-off lines is differentiated to obtain candidate boundary points between the tool cutting edge and the background, and the combination of points that is on the straightest line is selected from the combinations of each candidate boundary point, and this is used as a guide line for the cutting edge. Next, a differential image of the image of the cutting edge of the tool is obtained. The differential direction is the cutting edge direction. Next, pixels with large differential values of the differential image are extracted near the guide line, and the contour line of the cutting edge is extracted by connecting these pixels.

Japanese Patent Application Publication No. 8-257876 Japanese Patent Application Publication No. 11-351835

However, in Patent Document 1, worn surfaces appear darker than normal surfaces, making it difficult to selectively detect only worn surfaces. Therefore, it is not easy to automatically measure the amount of wear using the method in Patent Document 1.

In addition, in Patent Document 2, when it is desired to automatically measure the amount of wear, it is conceivable that the amount of wear can be detected by the fact that the worn surface appears slightly darker than the normal surface in the image of the tool cutting edge. However, the boundary between the worn surface and the normal surface is not clear, and it is not always possible to find the contour line of the cutting edge, which serves as a reference for measuring the amount of wear. As a result, it is difficult to accurately detect the amount of wear.

The object of the present invention is to provide a wear measurement device and a wear measurement method that can automatically measure the amount of wear on the cutting edge of a tool with high accuracy.

One aspect of the present invention is
A wear amount measuring method for measuring a wear amount by irradiating a measured object having a wear surface with light from a light source, capturing an image of the measured object, and identifying the wear surface of the measured object from the image obtained by capturing the image, comprising:
The angle of view of the light source with respect to the object to be measured can be adjusted to be reduced by using an angle of view adjustment unit,
a specular reflection specifying step of: placing a dummy object to be measured having a worn surface, setting the angle of view to a maximum value, adjusting the light irradiation direction and the image capture direction so that the worn surface of the dummy object to be measured is imaged brightly, repeating this adjustment while gradually decreasing the angle of view, and terminating this adjustment when the angle of view has been reduced to a minimum value, and specifying that the light irradiation direction and the image capture direction at this time are in a relationship that results in specular reflection with respect to the worn surface of the dummy object to be measured;
a wear surface identifying step of replacing the dummy object to be measured with the object to be measured while maintaining the light irradiation direction and the image capturing direction after the specular reflection position identifying step, setting the position and attitude of the object to be measured to be the same as those of the dummy object to be measured, maximizing the angle of view, capturing an image of the object to be measured, and identifying the wear surface;
The present invention relates to a method for measuring wear amount, comprising the steps of:

Another aspect of the present invention is
A wear amount measuring method for measuring a wear amount by irradiating a measured object having a wear surface with light from a light source, capturing an image of the measured object, and identifying the wear surface of the measured object from the image obtained by capturing the image, comprising:
The angle of view of the light source with respect to the object to be measured can be adjusted to be reduced by using an angle of view adjustment unit,
a specular reflection specifying step of: placing a dummy object to be measured having a worn surface, setting the angle of view to a maximum value, adjusting the light irradiation direction and the image capture direction so that the worn surface of the dummy object to be measured is imaged brightly, repeating this adjustment while gradually decreasing the angle of view, and terminating this adjustment when the angle of view has been reduced to a minimum value, and specifying that the light irradiation direction and the image capture direction at this time have a relationship such that the light irradiation direction and the image capture direction result in specular reflection with respect to the worn surface of the dummy object to be measured;
a wear surface identifying step of, after the specular reflection position identifying step, replacing the dummy measured object with the measured object while maintaining the light irradiation direction and image capturing direction, setting the position and attitude of the measured object to be the same as those of the dummy measured object, capturing an image of the measured object to identify a temporary wear surface, capturing an image of the measured object while gradually increasing the visible angle to calculate a change in the temporary wear surface, and identifying the temporary wear surface when the temporary wear surface becomes constant as the wear surface;
The present invention relates to a method for measuring wear amount, comprising the steps of:

The viewing angle adjustment section may be a cylinder having an opening with a diameter smaller than the light emitting surface of the light source.

The maximum viewing angle may be greater than or equal to 5° and less than or equal to 15°.

The minimum viewing angle may be 2° or less.

The method may further include a step of measuring the surface condition of the wear surface from the brightness distribution within the wear surface.

The present invention makes it possible to accurately identify the wear surface of the object being measured and automatically measure the amount of wear.

FIG. 1 is a diagram showing a configuration of a wear amount measuring device according to a first embodiment. FIG. 2 is a diagram showing the configuration of an angle of view adjustment unit 6. FIG. 2 is a diagram showing the relative positions of a light source 1, a camera 2, and a dummy tool 7. FIG. 4 is a diagram showing an example of a worn tool 4. A photograph of the worn cutting edge of an end mill. FIG. 13 is a diagram showing the configuration of a wear amount measuring device according to a second embodiment. FIG. 4 is a schematic diagram showing the state of the vicinity of the wear surface when an image of the cutting edge of a worn hob cutter is taken. A diagram showing the definition of the angle of view.

Specific examples of the present invention will be described below with reference to the drawings, but the present invention is not limited to these examples.

Figure 1 is a diagram showing the configuration of a wear amount measuring device of Example 1. The wear amount measuring device of Example 1 is a device that measures the wear amount of the cutting edge of a tool 4. As shown in Figure 1, the wear amount measuring device of Example 1 has a light source 1, a camera 2, and a calculation unit 3. The light source 1 corresponds to the light irradiation unit of the present invention, and the camera 2 corresponds to the image capturing unit of the present invention. The tool 4, which is the object to be measured, is placed on a stage 5, which supports the tool 4 so that it can rotate and move linearly. The position and attitude (angle) of the tool 4 are adjusted by the stage 5 so that the light from the light source 1 hits the cutting edge of the tool 4.

Figure 4 is an example showing the state in which the cutting edge of the tool 4 has been worn. As shown in Figure 4, a wear surface 4a has been generated by the wear of the cutting edge. In Figure 4, the dotted line indicates the cutting edge ridge before wear. The wear surface 4a has an angle different from other surfaces that make up the cutting edge, such as the flank surface or the scuff surface. In the wear amount measuring device of Example 1, the wear amount is calculated by identifying the range of this wear surface 4a by image processing. Note that wear as used in this specification includes not only wear caused by the cutting edge of the tool 4 being worn down, but also wear caused by chipping (chipping) and deformation, and refers to a state in which the shape has become different from the original shape.

The light source 1 is a device that irradiates light onto the cutting edge of the tool 4. The wavelength of the light of the light source 1 may be any wavelength band that is reflected by the tool 4 and can be captured by the camera 2. The light source 1 uses light with a light-emitting surface 8 of an appropriate size. For example, a light source with a viewing angle of 5° to 15° is used. If the viewing angle is within this range, the wear amount of the tool 4 can be measured more accurately. Here, the viewing angle of the light source 1 with respect to the tool 4 is defined as the angle between L1 and L2, as shown in FIG. 8, where L1 is the central axis of the light-emitting surface 8 of the light source 1, P is the intersection of L1 and the tool 4, and L2 is the straight line connecting the end of the light-emitting surface 8 and point P. The viewing angle of the light source 1 with respect to the dummy tool 7 described later is defined in the same manner.

A viewing angle adjustment unit 6 is provided near the light emission side of the light source 1. The viewing angle adjustment unit 6 is a device that performs control to reduce the viewing angle of the light emitted from the light source 1 with respect to the tool 4 and the dummy tool 7. The viewing angle adjustment unit 6 is used to adjust the positional relationship between the light source 1, the camera 2, and the tool 4, which will be described later.

The angle-of-view adjustment unit 6 is a device that adjusts the angle of view by using a cylinder 11 with an opening whose diameter is smaller than the light-emitting surface and covering the protruding part of the light source 1 with the cylinder 11, as shown in FIG. 2, for example. The angle-of-view adjustment unit 6 may also be an aperture.

It is preferable that the minimum value of the viewing angle of the light source 1 can be set to 2° or less by the viewing angle adjustment unit 6. This makes it easier to adjust the positional relationship between the light source 1, the camera 2, and the tool 4, as described below.

Camera 2 is a device that collects reflected light from the cutting edge of tool 4 using a lens, then captures the image using an imaging element such as a CCD to obtain digital image data.

The positional relationship between the light source 1, the camera 2, and the tool 4 is set so that when a dummy tool 7 is placed in place of the tool 4, the light source 1 and the camera 2 are arranged so that they are in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7 (see FIG. 3). In other words, the light source 1 and the camera 2 are arranged so that the angle formed by the direction of light irradiation from the light source 1 with respect to the wear surface 7a is equal to the angle formed by the image capturing direction of the camera 2 with respect to the wear surface 7a. Here, the dummy tool 7 is a tool whose cutting edge has been worn by actually using the same type of tool as the tool 4, and the position, range, and angle of the wear surface 7a are known. The wear surface 7a is a surface that has been created by wear of the cutting edge, and has an angle different from other surfaces that make up the cutting edge (for example, the rake face and the flank face).

The arrangement of the light source 1 and the camera 2 does not need to be in a strictly specular reflection relationship with respect to the wear surface 7a of the dummy tool 7, and some deviation from the specular reflection relationship is acceptable as long as the wear surface 4a of the tool 4 can be identified with sufficient accuracy. For example, the angle between the wear surface 7a and the light emission direction from the light source 1 is θ1, and the angle between the wear surface 7a and the light reception direction of the camera 2 is θ2, and 0.9≦(θ2/θ1)≦1.1 may be satisfied.

In addition, if there is variation in the angle of the wear surface 7a of the dummy tool 7, the relationship in which the arrangement of the light source 1 and the camera 2 with respect to the wear surface 7a of the dummy tool 7 results in specular reflection cannot be uniquely determined. In such a case, it is sufficient that the relationship results in specular reflection for a portion of the wear surface 7a. In particular, it is advisable to set the area in which specular reflection occurs to be as large as possible.

Since the positional relationship between the light source 1, the camera 2, and the dummy tool 7 is set as described above, the positional relationship between the light source 1, the camera 2, and the tool 4 is set so that the arrangement of the light source 1 and the camera 2 is in a regular reflection relationship or a relationship close to that with respect to the wear surface 4a of the tool 4. For example, the positional relationship between the light source 1, the camera 2, and the tool 4 is set so that the light intensity from the wear surface 4a of the tool 4 is 90% or more of the light intensity of the wear surface 7a when the arrangement of the light source 1 and the camera 2 is set to be in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7.

The calculation unit 3 is connected to the camera 2, and digital image data of the cutting edge of the tool 4 captured by the camera 2 is input to the calculation unit 3. The calculation unit 3 is a device that calculates the amount of wear from the image data. The calculation unit 3 is realized, for example, by an application program installed on a computer. The amount of wear is defined, for example, as the maximum value of the width of the worn surface in a direction perpendicular to the cutting edge ridge before wear. Alternatively, the amount of wear may be defined as the volume or mass lost due to wear.

Next, we will explain how to calculate the amount of wear on the cutting edge of tool 4 using the wear measurement device of Example 1.

As a preliminary preparation for measuring the wear amount of the tool 4, a dummy tool 7 is placed on the stage 5 in place of the tool 4, and the position of the light source 1 is adjusted. First, the position and attitude of the camera 2 are fixed, and the position and attitude of the dummy tool 7 are adjusted by the stage 5 so that the cutting edge of the dummy tool 7 is positioned in the light receiving direction of the camera 2. In order to facilitate the estimation of the cutting edge ridge of the tool 4 in the subsequent process, it is advisable to fix the attitude of the camera 2 so that the surface including the cutting edge ridge (for example, the rake surface) and the light receiving direction of the camera 2 are parallel. Next, the light of the light source 1 is irradiated onto the cutting edge of the dummy tool 7. The light angle of the light of the light source 1 is maximized. In other words, the cutting edge is not adjusted by the viewing angle adjustment unit 6. Then, the cutting edge of the dummy tool 7 is imaged by the camera 2. Here, the position and attitude of the light source 1 are roughly determined so that the wear surface 7a of the cutting edge of the dummy tool 7 is brighter than the other surfaces that make up the cutting edge.

Next, the angle of view of the light from the light source 1 is slightly reduced by the angle of view adjustment unit 6. Then, the cutting edge of the dummy tool 7 is imaged by the camera 2. The position and orientation of the light source 1 are adjusted again so that the worn surface of the cutting edge of the dummy tool 7 becomes brighter than the other surfaces.

The position and attitude of the light source 1 are repeatedly adjusted while the angle of view of the light from the light source 1 is gradually reduced by the angle of view adjustment unit 6, and finally the position and attitude of the light source 1 are adjusted with the angle of view of the light source 1 at its smallest by the angle of view adjustment unit 6. This makes it easy to set the positional relationship of the light source 1 and the camera 2 with respect to the wear surface 7a of the dummy tool 7 so that they are in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7.

In the first embodiment, the position and orientation of the camera 2 are fixed, and only the position and orientation of the light source 1 are adjusted. However, conversely, the position and angle of the light source 1 may be fixed, and only the position and angle of the camera 2 may be adjusted. Also, the positions and angles of both the light source 1 and the camera 2 may be adjusted.

In addition, it is not necessary to adjust the relative positions of the light source 1, camera 2, and dummy tool 7 using the angle of view adjustment unit 6 as described above. As long as the relative positions of the light source 1 and camera 2 relative to the wear surface 7a of the dummy tool 7 are in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7, the relative positions may be adjusted in any manner.

Next, the dummy tool 7 is removed from the stage 5, and the tool 4 for which the amount of wear will actually be measured is placed on the stage 5. At this time, the position and orientation of the tool 4 are set to be the same as those of the dummy tool 7. Furthermore, the positions and orientations of the light source 1 and the camera 2 are not changed. Therefore, the positional relationship between the light source 1 and the camera 2 is a relationship of regular reflection with respect to the wear surface 4a of the tool 4, or a relationship close to that.

The angle of view of the light source 1 is adjusted appropriately by the angle of view adjustment unit 6. Normally, there is variation in the angle of the wear surface 4a of the tool 4, and when the angle of view of the light source 1 is set to a minimum, the range of the wear surface 4a is calculated to be narrower than the actual range, and there is a risk that the range of the wear surface 4a cannot be adequately identified. In such a case, the angle of view of the light source 1 can be appropriately adjusted by the angle of view adjustment unit 6, making it possible to adequately identify the range of the wear surface 4a. The angle of view may be set to the maximum (the angle of view of the light source 1 itself) without controlling the angle of view by the angle of view adjustment unit 6.

Next, the cutting edge of the tool 4 is imaged by the camera 2, and the image data is processed by the calculation unit 3 to calculate the wear surface 4a.

Here, the positional relationship between the light source 1, the camera 2, and the dummy tool 7 was set so that the arrangement of the light source 1 and the camera 2 was in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7, so the positional relationship between the light source 1, the camera 2, and the tool 4 was also set so that the arrangement of the light source 1 and the camera 2 was in a regular reflection relationship or close to that with respect to the wear surface 4a of the tool 4.

Therefore, most of the light from the light source 1 is reflected by the wear surface 4a of the tool 4 and enters the camera 2, and the wear surface 4a of the tool 4 is imaged brightly. On the other hand, light reflected by other surfaces that make up the cutting edge of the tool 4 (surfaces that are not worn, such as the rake face and flank face) does not enter the camera 2, and the other surfaces are imaged dark. Therefore, the wear surface 4a of the tool 4 is imaged sufficiently brighter than the other surfaces.

Therefore, by extracting differences in brightness in the image data through simple image processing, the wear surface 4a of the tool 4 can be identified, and the amount of wear can be automatically measured.

For example, the boundary line of the wear surface 4a can be identified by extracting the boundary line of differences in brightness using image processing such as differentiation, and the wear surface 4a can be identified. The cutting edge ridge before wear can then be estimated by fitting a straight line, and the amount of wear can be calculated as the maximum value of the width of the wear surface 4a in the direction perpendicular to the cutting edge ridge. It is also possible to measure the surface condition of the wear surface 4a by measuring the brightness distribution within the wear surface 4a.

When the angle of view of the light source 1 is reduced by the angle of view adjustment unit 6, the range of the wear surface 4a may be determined to be smaller than the actual range due to the variation in the angle of the wear surface 4a. Therefore, the angle of view of the light source 1 may be gradually increased by the angle of view adjustment unit 6 to calculate the change in the range of the wear surface 4a, and the wear surface 4a when the change in the wear surface 4a becomes constant may be determined as the actual range of the wear surface 4a of the tool 4.

As described above, according to the wear amount measuring device of the first embodiment, the wear surface 4a caused by wear of the cutting edge of the tool 4 can be imaged so that it is brighter than other surfaces, and the wear surface 4a can be identified by simple image processing. Therefore, the wear amount of the tool 4 can be automatically measured easily and accurately.

Next, we will explain the results of imaging the worn portion of tool 4 using the wear amount measuring device of Example 1. Tool 4 and dummy tool 7 were end mills.

Figure 5 is a photograph of the wear surface 4a of a worn tool 4. Figure 5(a) shows an image of the wear surface 4a of the tool 4 taken using the wear amount measuring device of Example 1 with the light source 1, camera 2, and dummy tool 7 arranged for regular reflection, while Figure 5(b) shows an image of the wear surface 4a of the tool 4 taken with the light source 1, camera 2, and dummy tool 7 arranged for non-regular reflection.

As shown in FIG. 5(a), the light source 1 and the camera 2 are in a positional relationship that results in regular reflection or close to regular reflection with respect to the wear surface 4a of the tool 4, so the wear surface 4a is imaged brighter than the other surfaces that make up the cutting edge. Therefore, the range of the wear surface 4a can be identified by simple image processing, making it possible to automatically measure the amount of wear.

In contrast, in FIG. 5(b), the arrangement of the light source 1 and the camera 2 with respect to the wear surface 4a of the tool 4 does not result in regular reflection, so the other surfaces that make up the cutting edge are imaged brighter than the wear surface 4a, making it difficult to identify the wear surface 4a.

Figure 6 is a diagram showing the configuration of the wear amount measuring device of Example 2. As shown in Figure 6, the wear amount measuring device of Example 2 is provided with two light sources 1 in the wear amount measuring device of Example 1, and an angle adjustment unit 6 is provided near the light irradiation side of each of the two light sources. The other configuration is the same as that of the wear amount measuring device of Example 1. Hereinafter, the two light sources 1 are referred to as light sources 1A and 1B.

The positional relationship of the light sources 1A, 1B, the camera 2, and the tool 4 is set so that the light sources 1A and 1B are in the same relationship as in Example 1. In other words, the positional relationship of the light source 1A, the camera 2, and the tool 4 is set so that when the dummy tool 7 is placed in place of the tool 4, the light source 1A and the camera 2 are in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7. The positional relationship of the light source 1B, the camera 2, and the tool 4 is set so that when the dummy tool 7 is placed in place of the tool 4, the light source 1A and the camera 2 are in a regular reflection relationship with respect to the wear surface 7a of the dummy tool 7. Furthermore, the light sources 1A and 1B are arranged so that the angle of incidence of the light from the light source 1A and the angle of incidence of the light from the light source 1B with respect to the wear surface 7a of the dummy tool 7 are different. Alternatively, they may be arranged so that the incidence surfaces are different.

According to the wear amount measuring device of Example 2, similar to the wear amount measuring device of Example 1, the wear surface 4a of the tool 4 can be identified by simple image processing, and the wear amount of the tool 4 can be easily and accurately measured automatically. Furthermore, since the angle of incidence of light from light source 1A to the wear surface 7a of the dummy tool 7 is different from the angle of incidence of light from light source 1B, even if the wear surface 4a of the tool 4 is composed of multiple surfaces with different angles, the range of the wear surface 4a can be measured with high accuracy.

In the wear amount measuring device of Example 2, the number of light sources 1 is two, but it may be three or more. In this case, it is sufficient that the light sources 1 are arranged so that the angles of incidence of light from each light source 1 with respect to the wear surface 7a of the dummy tool 7 are different from each other. However, if the number of light sources 1 is too large, it may become difficult to image the wear surface 4a of the tool 4 sufficiently brighter than other surfaces. Therefore, it is preferable that the number of light sources 1 is three or less.

Next, we will explain the results of imaging the worn portion of tool 4 using the wear amount measuring device of Example 2. Tool 4 and dummy tool 7 were hob cutters.

Figure 7 is a diagram showing a schematic diagram of the state near the wear surface 4a when the wear surface 4a of the worn tool 4 is imaged. Figure 7(a) is a schematic diagram of an image taken using the wear amount measuring device of Example 2, in which light is irradiated from the left light source 1 of the two light sources 1 and no light is irradiated from the right light source 1. Figure 7(b) is a schematic diagram of an image taken, in the opposite manner to Figure 7(a), in which light is irradiated from the right light source 1 and no light is irradiated from the left light source 1. Figure 7(c) is a schematic diagram of an image taken with light irradiated from both of the two light sources 1. Figure 7(d) is a schematic diagram of an image taken with light irradiated using a coaxial ring light instead of the two light sources 1.

As shown in Figure 7(a), when only light from the light source 1 on the left side is irradiated, the left side area of the wear surface 4a of the tool 4 is imaged brighter than the other surfaces, but the right side area of the wear surface 4a of the tool 4 is dark, and it was found that the wear surface 4a cannot be identified with high accuracy.

In addition, as shown in FIG. 7(b), when only light from the light source 1 on the right side is irradiated, the right side area of the wear surface 4a of the tool 4 is imaged brighter than the other surfaces, but the left side area of the wear surface 4a of the tool 4 is dark, and it was found that the wear surface 4a cannot be identified with high accuracy.

In addition, as shown in FIG. 7(c), when light is irradiated from both the left and right light sources 1, the entire wear surface 4a is imaged brightly, and the other surfaces of the cutting edge are imaged darkly. Therefore, the entire wear surface 4a can be accurately identified by simple image processing, and automatic measurement of the amount of wear can be realized.

Also, as shown in Figure 7(d), when a coaxial ring light was used, the wear surface 4a of the tool 4 was imaged dark, and the front clearance surface was imaged bright. Therefore, it was difficult to identify the wear surface 4a. This is because when a coaxial ring light was used as the light source, the position of the light source and the camera 2 did not result in a regular reflection relationship with the wear surface 4a of the tool 4.

In the embodiment, the object to be measured is a tool, but any tool can be used; for example, the present invention can be used to measure the amount of wear of tools used in turning, gear skiving, chamfering, drilling, and the like. Furthermore, the present invention is not limited to measuring the amount of wear of tools, but can measure the amount of wear of any object that wears. For example, the amount of wear of a mold can be measured.

The wear amount measuring device of the present invention can be used to predict the amount of wear of a tool, determine when to replace the tool, and observe the surface condition of the wear surface of the tool.

1: Light source 2: Camera 3: Calculation unit 4: Tool 5: Stage 6: View angle adjustment unit 7: Dummy tool

Claims (6)

A wear amount measuring method for measuring a wear amount by irradiating a measured object having a wear surface with light from a light source, capturing an image of the measured object, and identifying the wear surface of the measured object from the image obtained by capturing the image, comprising:
The angle of view of the light source with respect to the object to be measured can be adjusted to be reduced by using an angle of view adjustment unit,
a specular reflection specifying step of: placing a dummy object to be measured having a worn surface, setting the angle of view to a maximum value, adjusting the light irradiation direction and the image capture direction so that the worn surface of the dummy object to be measured is imaged brightly, repeating this adjustment while gradually decreasing the angle of view, and terminating this adjustment when the angle of view has been reduced to a minimum value, and specifying that the light irradiation direction and the image capture direction at this time are in a relationship that results in specular reflection with respect to the worn surface of the dummy object to be measured;
a wear surface identifying step of replacing the dummy object to be measured with the object to be measured while maintaining the light irradiation direction and the image capturing direction after the specular reflection identifying step, setting the position and attitude of the object to be measured to be the same as those of the dummy object to be measured, maximizing the angle of view, capturing an image of the object to be measured, and identifying the wear surface;
A wear amount measuring method comprising the steps of: A wear amount measuring method for measuring a wear amount by irradiating a measured object having a wear surface with light from a light source, capturing an image of the measured object, and identifying the wear surface of the measured object from the image obtained by capturing the image, comprising:
The angle of view of the light source with respect to the object to be measured can be adjusted to be reduced by using an angle of view adjustment unit,
a specular reflection specifying step of: placing a dummy object to be measured having a worn surface, setting the angle of view to a maximum value, adjusting the light irradiation direction and the image capture direction so that the worn surface of the dummy object to be measured is imaged brightly, repeating this adjustment while gradually decreasing the angle of view, and terminating this adjustment when the angle of view has been reduced to a minimum value, and specifying that the light irradiation direction and the image capture direction at this time have a relationship such that the light irradiation direction and the image capture direction result in specular reflection with respect to the worn surface of the dummy object to be measured;
a wear surface identifying step of, after the specular reflection identifying step, replacing the dummy measured object with the measured object while maintaining the light irradiation direction and image capturing direction, setting the position and attitude of the measured object to be the same as those of the dummy measured object, capturing an image of the measured object to identify a temporary wear surface, capturing an image of the measured object while gradually increasing the visible angle to calculate a change in the temporary wear surface, and identifying the temporary wear surface when the temporary wear surface becomes constant as the wear surface;
A wear amount measuring method comprising the steps of: The wear amount measuring method according to claim 1 or 2, wherein the angle adjustment unit is a cylinder having an opening with a diameter smaller than the light emitting surface of the light source. The wear amount measuring method according to any one of claims 1 to 3, wherein the maximum value of the prospect angle is 5° or more and 15° or less. The wear measurement method according to any one of claims 1 to 4, wherein the minimum value of the projection angle is 2° or less. 6. The wear amount measuring method according to claim 1, further comprising the step of measuring a surface condition of the worn surface of the object to be measured from a luminance distribution within the worn surface of the object to be measured .